Abstracts CAN bus communication to MKS SERVO57D/42D/35D/28D stepper motor driver modules. More...

#include <mks_stepper_controller.hpp>

Collaboration diagram for MksStepperController:

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Public Member Functions
	MksStepperController (const std::string &can_interface, std::shared_ptr< const std::unordered_set< uint16_t >> motor_ids, const uint8_t norm_factor=1)
	Initializes an MksStepperController. More...

	~MksStepperController () noexcept
	Destroys an MksStepperController.

bool	setSpeed (const uint16_t motor, const int16_t speed, const uint8_t acceleration=0)
	Sends a MksCommands::SET_SPEED command to set the speed of a motor. More...

bool	sendStep (const uint16_t motor, const uint32_t num_steps, const int16_t speed, const uint8_t acceleration=0)
	Sends a MksCommands::SEND_STEP command to move a motor a fixed number of steps. More...

bool	seekPosition (const uint16_t motor, const int32_t position, const int16_t speed, const uint8_t acceleration=0)
	Sends a MksCommands::SEEK_POS_BY_STEPS command to move a motor to specific step position. More...

bool	getPosition (const uint16_t motor)
	Sends a MksCommands::CURRENT_POS command to query the current position of a motor in steps. More...

bool	isSetup () const
	Returns whether the CAN bus connection has been fully established. More...

void	update (const std::chrono::nanoseconds &timeout=std::chrono::nanoseconds::zero())
	Polls for CAN messages. More...

Public Attributes
boost::signals2::signal< void(uint16_t, bool)>	ESetSpeed
	Boost signal triggered when setSpeed responses are received. More...

boost::signals2::signal< void(uint16_t, MksMoveResponse)>	ESendStep
	Boost signal triggered when sendStep responses are received. More...

boost::signals2::signal< void(uint16_t, MksMoveResponse)>	ESeekPosition
	Boost signal triggered when seekPosition responses are received. More...

boost::signals2::signal< void(uint16_t, int32_t)>	EGetPosition
	Boost signal triggered when getPosition responses are received. More...

Protected Member Functions
void	handleCanMessage (const std::vector< uint8_t > &message, drivers::socketcan::CanId &info)
	Handles received CAN messages and sends out signals as appropriate. More...

Signal Processing Helper Functions

Helper functions for decoding the parameters of Sysex commands processed by handleSysex before forwarding to their associated signal.

Parameters

message the de-firmatified Sysex payload

std::unique_ptr< drivers::socketcan::SocketCanReceiver > can_receiver

std::unique_ptr< drivers::socketcan::SocketCanSender > can_sender

std::shared_ptr< const std::unordered_set< uint16_t > > motor_ids

const uint8_t norm_factor

void handleESetSpeed (const std::vector< uint8_t > &message, drivers::socketcan::CanId &info)

void handleESendStep (const std::vector< uint8_t > &message, drivers::socketcan::CanId &info)

void handleESeekPosition (const std::vector< uint8_t > &message, drivers::socketcan::CanId &info)

void handleEGetPosition (const std::vector< unsigned char > &message, drivers::socketcan::CanId &info)

Detailed Description

Abstracts CAN bus communication to MKS SERVO57D/42D/35D/28D stepper motor driver modules.

Responses are conveyed through Boost signals.

Interpolated Normalisation

To get around the limitations introduced by specifying speeds under nominal conditions, a technique which will be referred to as "interpolated normalisation" is used to normalise the units of speed to RPM, assuming 200 full-steps per revolution. In other words, the unit of speed shifts from 160/3 steps/s to 200 steps/min.

This is achieved by micro-stepping the motor at a specified interpolation factor. For example, if an interpolation factor of 16 is used, and the motor is requested to move at 2 RPM, the motor will actually move at 6400 steps/min.

An interpolation factor of 1 can be used to disable interpolation.

Constructor & Destructor Documentation

◆ MksStepperController()

MksStepperController::MksStepperController	(	const std::string &	can_interface,
		std::shared_ptr< const std::unordered_set< uint16_t >>	motor_ids,
		const uint8_t	norm_factor = `1`
	)

Initializes an MksStepperController.

Parameters

can_interface	SocketCAN network interface corresponding to the CAN bus
motor_ids	CAN IDs for the motor controllers, used to filter CAN messages so other devices' messages aren't attempted to be decoded
norm_factor	interpolated normalisation factor to use, see Interpolated Normalisation; defaults to off

Member Function Documentation

◆ getPosition()

bool MksStepperController::getPosition ( const uint16_t motor )

Sends a MksCommands::CURRENT_POS command to query the current position of a motor in steps.

Parameters

motor the ID of the motor to query

Returns: true if transmitted over the CAN bus

◆ handleCanMessage()

void MksStepperController::handleCanMessage	(	const std::vector< uint8_t > &	message,
		drivers::socketcan::CanId &	info
	)

protected

Handles received CAN messages and sends out signals as appropriate.

Parameters

message	the message payload
info	auxiliary information associated with the message, e.g. driver ID, bus time

◆ isSetup()

bool MksStepperController::isSetup ( ) const

Returns whether the CAN bus connection has been fully established.

Returns: true if so

◆ seekPosition()

bool MksStepperController::seekPosition	(	const uint16_t	motor,
		const int32_t	position,
		const int16_t	speed,
		const uint8_t	acceleration = `0`
	)

Sends a MksCommands::SEEK_POS_BY_STEPS command to move a motor to specific step position.

Since this command seeks a position, the sign of the speed is ignored.

Parameters

motor	the ID of the motor to move
position	the target position in number of steps from the motor's zero point, maximum of 2^23 - 1
speed	the signed target speed to set the motor to, in RPM; note that the absolute value is taken
acceleration	the speed ramp profile, see MksTest.Constants.MAX_ACCEL; defaults to instantaneous

Returns: true if transmitted over the CAN bus

◆ sendStep()

bool MksStepperController::sendStep	(	const uint16_t	motor,
		const uint32_t	num_steps,
		const int16_t	speed,
		const uint8_t	acceleration = `0`
	)

Sends a MksCommands::SEND_STEP command to move a motor a fixed number of steps.

Direction is controlled by the sign of the target speed. Response callbacks are available through ESendStep.

Parameters

motor	the ID of the motor to move
num_steps	the number of steps to move, maximum of 2^24 - 1
speed	the signed target speed to set the motor to, in RPM
acceleration	the speed ramp profile, see MksTest.Constants.MAX_ACCEL; defaults to instantaneous

Returns: true if transmitted over the CAN bus

◆ setSpeed()

bool MksStepperController::setSpeed	(	const uint16_t	motor,
		const int16_t	speed,
		const uint8_t	acceleration = `0`
	)

Sends a MksCommands::SET_SPEED command to set the speed of a motor.

Response callbacks are available through ESetSpeed. See MksTest.Constants.MAX_SPEED for speed limits.

Parameters

motor	the ID of the motor to control
speed	the signed target speed to set the motor to, in RPM
acceleration	the speed ramp profile, see MksTest.Constants.MAX_ACCEL; defaults to instantaneous

Returns: true if transmitted over the CAN bus

◆ update()

void MksStepperController::update ( const std::chrono::nanoseconds & timeout = std::chrono::nanoseconds::zero() )

Polls for CAN messages.

If an applicable message is received, the appropriate event is signalled.

Parameters

timeout maximum time to wait for a message to appear on the bus

Member Data Documentation

◆ EGetPosition

boost::signals2::signal<void(uint16_t, int32_t)> MksStepperController::EGetPosition

Boost signal triggered when getPosition responses are received.

Parameters

1st	[uint8_t] motor ID
2nd	[int32_t] motor position in steps

◆ ESeekPosition

boost::signals2::signal<void(uint16_t, MksMoveResponse)> MksStepperController::ESeekPosition

Boost signal triggered when seekPosition responses are received.

Parameters

1st	[uint8_t] motor ID
2nd	[MksMoveResponse] current movement status

◆ ESendStep

boost::signals2::signal<void(uint16_t, MksMoveResponse)> MksStepperController::ESendStep

Boost signal triggered when sendStep responses are received.

Parameters

1st	[uint8_t] motor ID
2nd	[MksMoveResponse] current movement status

◆ ESetSpeed

boost::signals2::signal<void(uint16_t, bool)> MksStepperController::ESetSpeed

Boost signal triggered when setSpeed responses are received.

Parameters

1st	[uint8_t] motor ID
2nd	[bool] 1 if movement succeeded

The documentation for this class was generated from the following files:

include/umrt-arm-firmware-lib/mks_stepper_controller.hpp
src/mks_stepper_controller.cpp

Public Member Functions

Public Attributes

Protected Member Functions

Signal Processing Helper Functions

Detailed Description

Interpolated Normalisation

Constructor & Destructor Documentation

◆ MksStepperController()

Member Function Documentation

◆ getPosition()

◆ handleCanMessage()

◆ isSetup()

◆ seekPosition()

◆ sendStep()

◆ setSpeed()

◆ update()

Member Data Documentation

◆ EGetPosition

◆ ESeekPosition

◆ ESendStep

◆ ESetSpeed